Google, Bing and Yahoo keep their search engine algorithm close to their heart. They are always hashing and rehashing the process in order to improve the process of search on the internet. To be an effective search engine optimization company, you have to be aware of the behavioural of search engines. Unfortunately, there are no manuals for Google or Bing algorithms, and to learn their behaviours you need to study them closely. An effective SEO company will have in-depth SEO labs and diagnostics tools to determine behavioural changes of these search engines. Companies will need to be reactive in applying principles they discover through their ongoing rigorous study and monitor of the more popular search engines.
As a webmaster, you have to be careful who you choose to handle your next SEO campaign. Make sure you only listen to a professional seo consultant that backs up his promises through facts and figures provided by his company.
Remember, there are no shortcuts to SEO. There really are only three things you need to focus on when it comes to SEO

Link Building – You need to build relationships with quality related websites and get them to link back to your site.

Age – You need to maintain this growth for a long period of time. Google recognizes that your back links build steadily over time (no harsh spikes or you might get penalized) and your quality content grows. The more mature your website gets the better.

The reality of the situation is item 1 above rests on your shoulders. Item 2, you could probably hire a trusted SEO company to help you build your backlinks. Item 3, well, that takes a bit of time and patience ;).